Detection of rogue software applications

ABSTRACT

Software applications are analyzed to determine if they are legitimate applications and warnings are provided to users to avoid installation and/or purchases of unnecessary and/or potentially harmful software based on comparisons of user-interface characteristics of the software applications to visual characteristics of authentic applications to determine to what extent they match (or do not match) or are attempting to mirror the legitimate application.

FIELD OF THE INVENTION

The invention relates generally to computer security, and, morespecifically, the identification of rogue software applications thatdeceive users into purchasing the rogue software.

BACKGROUND

The advance of computer and networking technologies has resulted in asignificant increase in the number of people who use computers in theirdaily lives to conduct business, communicate with friends andco-workers, and store information. In performing these functions, usersare often required to provide personally-identifiable and/or sensitiveprivate information such as user names, passwords, account numbers,birth dates, social security numbers and credit card numbers. Becausethis information can be used for nefarious purposes, such as stealingidentities, executing fraudulent purchases and other similar schemes, anentire class of software has evolved with the sole purpose of covertlygathering and transmitting this information to third parties. Suchsoftware, often referred to as “malware” or “spoof” software, comes inmany forms and is designed to infiltrate a computer system such that itsdetection and removal is very difficult, especially for the casualcomputer user.

In response to these threats, legitimate computer software companieshave introduced so-called “Anti-Virus” software, which is designed toidentify and remove malware, spyware, and other potentially threateningapplications. In some instances, the anti-virus software operates as anongoing process and when new software is introduced onto the machine,the anti-virus software performs a pre-installation scan or file checkto determine if the software is legitimate even before it is installedon the computer. These applications often present the user with a screenor other visual message that indicates a virus or other malware wasfound or is attempting to install itself on the users machine, andinstruct the user to take action. For example, the user may decide theapplication is legitimate and allow the installation, she may ask thatthe application be quarantined, or have the software removed.

With the onslaught of damaging viruses and computer-based identitythreats, anti-virus software has become a very large industry and usersroutinely purchase new applications. Some developers, however, havetaken advantage of this vulnerability and now present such “warning”screens even without any evidence of malware or viruses on a computer,knowing that a large percentage of users will accept the installation ofsuch software as a precaution. These applications often require users topurchase unneeded applications, and, in some cases, install malware orspyware of their own.

These applications, referred to herein as “rogue” software, essentiallyprey on the fears and concerns of consumers by focusing on a market withhigh demand (e.g., anti-virus, password management, browser plug-ins,etc.) but offer substandard products. To increase their appeal,developers of rogue software design their applications with a look andfeel similar to that of reputable software applications, furtherconfusing users. Recently, consumers have begun identifying these rougeprograms and are demanding that legitimate anti-virus and malwaredetection applications trap these applications as well. What is needed,therefore, is a method and system for positively identifying roguesoftware applications that are designed to appear as legitimateapplications, but in fact are not.

SUMMARY OF THE INVENTION

In various embodiments of the present invention, software applicationsare analyzed to determine if they are legitimate applications andwarnings are provided to users to avoid installation and/or purchases ofunnecessary and/or potentially harmful software. This is achieved, inpart, by comparing certain characteristics of potentially “rogue”software to the same or similar characteristics of known, legitimateapplications. In addition to using binary signature detection methodsand behavioral functions, user-interface characteristics are used todetermine if an application is legitimate. These visual characteristicscan be compared to visual characteristics of other applications todetermine to what extent they match (or do not match) or are attemptingto mirror the legitimate application.

As used herein, “rogue” software generally means a software product thatsubstantially mimics the look and feel of another legitimate softwareproduct, but not its functionality. Generally, the rogue softwaremasquerades as a legitimate product, often as an anti-virus orcomputer-maintenance/performance-enhancement software, and convinces auser to buy the fake product. Thus in some ways, the rogue software isanalogous to a phishing website that presents itself as an authenticwebsite to a user. The conventional anti-virus and/or malware-detectionapplications may not adequately protect a user from a rogue softwarebecause it typically does not perform any harmful actions on a computer(e.g., deleting files, accessing passwords, etc.), and hence, may not bedetected by the conventional applications.

In order to facilitate detection of rogue software products, features ofthe user-interface (UI) of an offered software are analyzed. Someexemplary UI features include the window title name, names of menubuttons, types of components in the UI (e.g., progress bar, lists,buttons, etc.), image files associated with the offered software,dialogue names, and colors. From the downloaded executable and/or datafiles associated with an offered software product, the various UIfeatures are extracted. These features are compared with the knownfeatures of legitimate products, and a potentially rogue software isdetected if the extracted features and the known features are similarbut do not match exactly or nearly exactly. In some instances,components of the downloaded executable and/or data files such asdigital signatures, etc. are also inspected to determine whether theoffered software product is a rogue product.

Accordingly, in one aspect, a method for determining the legitimacy of asoftware application being presented to a user of a computing deviceincludes programmatically detecting the execution of a softwareapplication on a computing device, during which user interfacecharacteristics of the software application are collected and stored ina memory. For example, one method to collect such user interfacecharacteristics on systems using the Microsoft Windows Operating System(OS) is to utilize one or more of the OS Application ProgrammingInterfaces (APIs) provided with the OS. The collected user interfacecharacteristics are compared to known user interface characteristics oflegitimate software applications and if a similarity between thecollected user interface characteristics and the known user interfacecharacteristics surpasses a predefined similarity threshold, analyzingadditional characteristics of the executing software application todetermine whether the application is a legitimate software application.

The computing device can be a personal computer, a tablet computer, agame console, or a mobile communications device. The user interfacecharacteristics may be one or more of window title names, screen controlnames, screen control components, progress bars, lists, buttons, imagefiles, dialog box names, colors, and system tray settings. Thelegitimate software applications comprise anti-virus applications, andthe executing software application may be a rogue software applicationmasquerading as an anti-virus application. The additionalcharacteristics may include a digital signature, a source location, abinary signature of the executing software application, an operatingsystem device driver, and/or an operating system kernel driver.

In some embodiments, a determination is made as to whether the executingsoftware has been digitally signed, and, if not, the executing softwareis classified as rogue software. The source location from which theexecuting software was transmitted to the computing device may also bedetermined and if not known to be an authentic source of legitimatesoftware applications, the executing software is classified as roguesoftware. Further, a binary signature of the executing software may becalculated or determined, and if it does not match a binary signature ofa known legitimate software application, the executing software isclassified as rogue software. In each case, the user may then bepresented with a message indicating the software is rogue.

In certain implementations, execution of the software is forced toterminate, and the files associated with the application are quarantinedfor subsequent deletion from the computing device. Again, the user maybe presented with a message suggesting and/or confirming the deletion ofthe software application from the device.

In another aspect, a system for analyzing determining the legitimacy ofa software application being presented to a user of a computing deviceincludes computer-executable instructions stored on a memory device.When executed by a processor, the instructions programmatically detectthe execution of a software application on a computing device duringwhich interface characteristics of the software application arecollected and stored in a memory. The instructions further cause knownuser interface characteristics of legitimate software applications to beretrieved from a database, and programmatically compare the collecteduser interface characteristics to the known user interfacecharacteristics. If a similarity between the collected user interfacecharacteristics and the known user interface characteristics surpasses apredefined similarity threshold, the instructions analyze additionalcharacteristics of the executing software application to determinewhether the application is a legitimate software application.

In some implementations, the instructions further determine if theexecuting software has been digitally signed, if the source locationfrom which the executing software was transmitted to the computingdevice is an authentic source of known legitimate software applications,and/or if the binary signature of the executing application matches abinary signature of a known legitimate software application and, if oneor more of these conditions are not met, the executing software isclassified as rogue software. In some instances the user is presentedwith a message indicating the software is rogue software. In someinstances, the instructions force termination of the executing softwareapplication and quarantine the files associated with the executingsoftware application for subsequent deletion from the computing device.The software may also be deleted from the computing device, andappropriate messages presented to the user.

Other aspects and advantages of the invention will become apparent fromthe following drawings, detailed description, and claims, all of whichillustrate the principles of the invention, by way of example only.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the sameparts throughout the different views. Also, the drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles of the invention.

FIG. 1 schematically depicts an exemplary computing device and systemcomponents for performing the methods described herein according to oneembodiment of the invention.

FIG. 2 shows a flow diagram of the steps performed in identifying andremediating potentially rogue software when presented to a user of acomputing device according to one embodiment of the invention.

FIG. 3 shows an exemplary screen image of a software application thatmay be analyzed using the methods and systems described herein.

DETAILED DESCRIPTION

Referring to FIG. 1, a computing device 100 on which various embodimentsof the invention may be implemented includes a stored memory 115, one ormore processors 110 and a display 105. In some embodiments, the devicemay include other components such as user input mechanisms such as akeyboard, mouse, pointer and the like. In other cases (or in combinationwith these input mechanisms) the display 105 may also provide user inputfunctionality using, for example, touch screen technology as known inthe art. Although FIG. 1 shows a single device 100, this areillustrative only and is meant to include devices such as cell phones,smart phones, netbooks, wireless devices, gaming consoles, pad computersand/or personal digital assistants (PDAs). The device 100 is typicallyconnected to a communication network (e.g., a private network, alocal-area network, a wireless network, the Internet, etc.) in order tosend and receive messages and data from other devices.

The stored memory 115 stores applications and data that are used by thedevice to perform functions as directed by the user of the device. Onesuch application that is routinely installed and used on the device isanti-virus software, which assists the user in identifying andeliminating unwanted software, and/or restoring systems settings toproper values. Examples of unwanted software include, for example,malware, keyboard loggers, tracking cookies, viruses, and the like,which are typically installed on the device 100 without the user'sknowledge or consent. Because the unwanted software can have such adetrimental impact on the user's device and/or compromise the user'sprivacy and security, users are especially prone to purchasinganti-virus software when they are informed of a potential infection.

Unscrupulous software vendors are aware of this vulnerability and havedevised schemes to take advantage of users' naïveté in this regard. Forexample, software vendors have designed applications that mimic thelook, feel and operation of legitimate anti-virus applications that,when executing, lure the users into a false sense of threat and, basedon this fear, encourage the user to purchase the software unnecessarily.Unlike traditional malware and viruses, these applications do notperform any “harmful” functions (e.g., deleting files, changing registryentries, creating tracking cookies, or covertly transmitting data). Assuch, the execution of these applications is not detected byconventional anti-virus software applications. Using the techniques andsystems described herein, however, users can be notified when theserogue applications are presented to them and can be informed that theapplications are not authentic anti-virus applications.

According to various embodiments of the invention, and referring to FIG.2, a user operating a computing device may be presented with a warningscreen, pop-up ad, email or other message (generally referred to hereinas a “potentially rogue software application” or “application”) thatindicates (usually falsely) that their device is under threat frommalware, a virus, or other potentially damaging software. The executionof this “application” is first detected on the device (STEP 205). Thedetection may take place by monitoring the Windows messaging queue fornew display commands containing certain elements. Once detected, varioususer interface characteristics are then identified and collected (STEP210). These characteristics may include, for example, window titlenames, screen control names, screen control components, progress bars,lists, buttons, image files, dialog box names, colors, text, and/orsystem tray settings. The specific characteristics may be stored inmemory for subsequent comparison.

Separately, a database of visual characteristics of known authenticanti-virus software applications may be maintained. In some instances,the database may be a centrally-managed database (e.g., by an anti-virusapplication vendor, for example) and accessed remotely over theInternet, or, in some cases, the database may be stored locally on thedevice itself. If stored locally, the local database may be updatedperiodically (e.g., every week, month, etc.), on demand, or whenever thecentral database is updated. In any instance, user interfacecharacteristics from the authentic anti-virus applications are retrievedfrom the database (STEP 215) and compared to those collected from theexecuting application (STEP 220). The comparison may include comparingobject names, naming conventions, text, binary representations ofimages, as well as other comparisons to determine a degree of matchbetween the application being analyzed and applications known to beauthentic. If none of the characteristics match, or so few match that itis unlikely that the application not being passed off as anti-virussoftware (DECISION STEP 225), the process ends (STEP 230). If, however,the degree of match is above some predetermined threshold (e.g., morethan 75% of the components in a known anti-virus application exist inthe potentially rogue software) additional characteristics are thenanalyzed (STEP 235).

For example, if the application is now suspected as being roguesoftware, characteristics such as the binary signature of the executingapplication may be captured and compared to those of applications knownto be authentic applications. In some cases, the comparison may belimited to those applications to which a high degree of match among theuser interface characteristics was made. In other instances, theapplication may be analyzed to determine if it has a digital signatureassociated with it, as most rogue applications do not. Further, in someimplementations it is feasible to determine the source from which theapplication was sent to the device, and that source (e.g., a URL, IPaddress, email address, or other uniquely identifiable information) maybe captured and compared to those of authentic applications. If thesecharacteristics do not match those of applications known to be authentic(DECISION STEP 240) the applications are then classified as rogueapplications.

Once classified as such, the users may be notified and remediation maythen take place (STEP 245). For example, the user may be presented witha dialog box informing him that the application screen being presentedis from a rogue application, and that there are in fact no known threatsto his device, and any suggestions to execute or purchase theapplication should be ignored. In some versions, the process maycontinue by searching for and removing any components of the rogueapplication present on the device. In still other versions, a digitalsignature, hash, or other numeric representation of the application orits components may be derived and stored and/or transmitted to a centralrepository for tracking such applications.

FIG. 3 provides an exemplary screen capture 300 from an applicationdetermined to be rogue software using the above-described techniques.The user interface components that make up the screen 300 that may becompared to those of authentic anti-virus applications include thewindow name, “Antivirus Plus (Unregistered)” 305, an image (typically a.jpg file) of shield 310 that is very similar to an image used in anauthentic application and buttons 315 having text descriptions such as“privacy,” “security,” “scan” and the like. Other components include aprogress bar 320 indicating the status of a scan, text suggesting theuser “get full protection” 325 or “purchase the application now,” acolor and menu scheme that matches known application schemes 330 and/ora listing of system scan results 335.

Each functional component described above may be implemented asstand-alone software components or as a single functional module. Insome embodiments the components may set aside portions of a computer'srandom access memory to provide control logic that affects theinterception, scanning and presentation steps described above. In suchan embodiment, the program or programs may be written in any one of anumber of high-level languages, such as FORTRAN, PASCAL, C, C++, C#,Java, Tcl, PERL, or BASIC. Further, the program can be written in ascript, macro, or functionality embedded in commercially availablesoftware, such as EXCEL or VISUAL BASIC.

Additionally, the software may be implemented in an assembly languagedirected to a microprocessor resident on a computer. For example, thesoftware can be implemented in Intel 80×86 assembly language if it isconfigured to run on an IBM PC or PC clone. The software may be embeddedon an article of manufacture including, but not limited to,computer-readable program means such as a floppy disk, a hard disk, anoptical disk, a magnetic tape, a PROM, an EPROM, or CD-ROM.

The invention can be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The foregoingembodiments are therefore to be considered in all respects illustrativerather than limiting on the invention described herein.

What is claimed is:
 1. A method for determining the legitimacy of asoftware application provided to a user of a computing device, themethod comprising using at least one data processing device:programmatically detecting that the software application is resident onthe computing device; extracting visual user interface characteristicsfrom at least one of an executable file and data files associated withthe software application; collecting and storing the visual userinterface characteristics of the software application in a memory;programmatically comparing the collected visual user interfacecharacteristics to known visual user interface characteristics of atleast one known legitimate software application; when a similaritybetween the collected visual user interface characteristics and theknown visual user interface characteristics surpasses a predefinedsimilarity threshold, analyzing at least one additional characteristicof the software application, wherein the at least one additionalcharacteristic comprises at least one of a digital signature, a sourcelocation and a binary signature; and terminating the softwareapplication and quarantining the files associated with the softwareapplication for subsequent deletion from the computing device when theat least one additional characteristic is indicative of rogue software.2. The method of claim 1, wherein the computing device comprises one ofa personal computer, a tablet computer, a game console, or a mobilecommunications device.
 3. The method of claim 1, wherein the visual userinterface characteristics comprise at least one of window title names,screen control names, screen control components, progress bars, lists,buttons, image files, dialog box names, colors, and system traysettings.
 4. The method of claim 1, wherein the legitimate softwareapplication comprises an anti-virus application.
 5. The method of claim4, wherein the software application is a rogue software applicationmasquerading as an authentic anti-virus application.
 6. The method ofclaim 1, further comprising determining if the software application hasbeen digitally signed, and, if not, classifying the software applicationas rogue software and presenting the user with a message indicating assuch.
 7. The method of claim 1, further comprising determining if thesource of the software application is a source of known legitimatesoftware applications, and if not, classifying the software applicationas rogue software and presenting the user with a message indicating assuch.
 8. The method of claim 1, further comprising determining thebinary signature of the software application and determining if thebinary signature matches a known binary signature of a known legitimatesoftware application, and if not, classifying the software applicationas rogue software and presenting the user with a message indicating assuch.
 9. The method of claim 1, further comprising presenting the userwith a message recommending deletion of the software application. 10.The method of claim 9, further comprising deleting the softwareapplication from the computing device in response to user input.
 11. Asystem for determining the legitimacy of a software application providedto a user of a computing device, the system comprising: at least onememory component for storing computer-executable instructions; and atleast one processor configured to execute computer-executableinstructions stored in the at least one memory, which when executed:programmatically detect that the software application is resident on thecomputing device; extract visual user interface characteristics from atleast one of an executable file and data files associated with thesoftware application; collect and store visual user interfacecharacteristics of the software application; programmatically comparethe collected visual user interface characteristics to the known visualuser interface characteristics of at least one known legitimate softwareapplication; when a similarity between the collected visual userinterface characteristics and the known visual user interfacecharacteristics surpasses a predefined similarity threshold, analyze atleast one additional characteristic of the software application, whereinthe at least one additional characteristic comprises at least one of adigital signature, a source location and a binary signature; andterminate the software application and quarantine the files associatedwith the software application for subsequent deletion from the computingdevice when the at least one additional characteristic is indicative ofrogue software.
 12. The system of claim 11, wherein the computing devicecomprises one of a personal computer, a tablet computer, a game console,or a mobile communications device.
 13. The system of claim 11, whereinthe visual user interface characteristics comprise at least one ofwindow title names, screen control names, screen control components,progress bars, lists, buttons, image files, dialog box names, colors,and system tray settings.
 14. The system of claim 11, wherein the atleast one known legitimate software application comprises an anti-virusapplication.
 15. The system of claim 11, wherein the instructions whenexecuted determine if the software application has been digitallysigned, and, if not, classify the software application as rogue softwareand present the user with a message indicating as such.
 16. The systemof claim 11, wherein the instructions when executed determine if thesource of the software application is a source of known legitimatesoftware applications, and if not, classify the software application asrogue software and present the user with a message indicating as such.17. The system of claim 11, wherein the instructions when executeddetermine the binary signature of the software application and determineif the binary signature matches a known binary signature of a knownlegitimate software application, and if not, classify the softwareapplication as rogue software and present the user with a messageindicating as such.
 18. The system of claim 11, wherein the instructionswhen executed present the user with a message recommending deletion ofthe software application.
 19. The system of claim 18, wherein theinstructions when executed delete the software application from thecomputing device.
 20. A non-transitory program storage medium,comprising instructions encoded thereon that when executed by acomputer: detect that a software application is resident on thecomputing device; extract visual user interface characteristics from atleast one of an executable file and data files associated with thesoftware application; collect and store the visual user interfacecharacteristics of the software application in a memory; compare thecollected visual user interface characteristics to known visual userinterface characteristics of at least one known legitimate softwareapplication; when a similarity between the collected visual userinterface characteristics and the known visual user interfacecharacteristics surpasses a predefined similarity threshold, analyze atleast one additional characteristic of the software application, whereinthe at least one additional characteristic comprises at least one of adigital signature, a source location and a binary signature; andterminate the software application and quarantine the files associatedwith the software application for subsequent deletion from the computingdevice when the at least one additional characteristic is indicative ofrogue software.
 21. The method of claim 1, wherein the extracting isperformed while the software application is not executing on thecomputing device.
 22. The system of claim 11, wherein the at least oneprocessor is configured to extract the visual user interfacecharacteristics while the software application is not executing on thecomputing device.